The current study tested the impact of different messaging interventions on changing attitude and behaviour in relation to Red and Processed Meat Consumption (RPMC). The study compared the effectiveness of receiving fourteen daily messages on the health, environment, or health + environment benefits of reduced RPMC, against a no message control condition. All three intervention conditions also received daily reminders of the goal regarding RPMC and were asked to record RPMC using a food diary. Participants in the control condition were only asked to use a food diary to record daily food intake. Behaviour and attitude in relation to RPMC of all participants were assessed at Time 1 (pre-message), Time 2 (immediately post-message, two weeks later) and Time 3 (one month later again). Participants were Italian undergraduates (at Time 1 N = 322) randomly allocated to one of the four conditions. Only those completing all measures at all time points were retained for analysis (N = 241). Results showed that health message condition and environment message condition, but not health + environment messages condition, were effective in increasing a positive attitude towards reduced RPMC compared to the control condition. Attitude mediated the effects of health condition and environmental condition on the reduction of behaviour. The effects of health and environment messages on attitude and behaviour persisted for one month after the end of the intervention. Implications for devising effective messaging intervention to change RPMC are discussed.